Tyre plaque / FAQ and hand book - please explain

[Ozzy119]

OK...so I'm bit confused about this now......

I have been reading quite a bit on changing tyres. Plenty of people out there with various setups and opinions.

Please explain: my tyre plaque inside my drivers door shows various wheel options. I have 255/60/R18 and the plaque says load rating 112. But the FAQ here says handbook suggests 110 and that the plaque allows 109. The only way I can see 109 allowed, as per the plaque, is if you had R20's on.

So i'm puzzled as the A/T tyres I'm favouring have a 110 rating on 18" rims.

Surely that isn't allowed, based in what the plaque is saying?

[101RRS]

The section on the plaque that lists different wheel and tyres sizes has heading that indicates these are Recommended sizes and load ratings.

Under that it gives the lowest ratings you are allowed can go to - on my RRS it is 980kg or 106. Your D3/D4 will have slightly higher ratings.

I would exceed the ratings listed in the recommended section to be on the safe side.

Garry

[gghaggis]

if you think about it, the total weight load on the tyre should be independent of the rim size, so the minimum stated load should suffice.

The recommended figures depend on what's available at time of stamping. And there are many tyre sizes it doesn't cover, hence the minimum.

Cheers,

Gordon

[MadJax]

I am the same boat. Tyre fitters are not happy to supply 110 on 18inch wheels as the plaque states

235/70 R17 111H
255/60 R18 112V
255/55 R19 111V
255/50 R20 109Y

However the manual states that winter tyres can have a different rating
235/65 R18 110H
255/55 R19 111H
255/50 R29 109H
So could I make an assumption that ATR tyres are like winter tyres and the 110 load rating makes it all OK.
I'm looking at Mickey Thompson 285/60R18 which have the 110 load rating.

[gghaggis]

Each state varies a little, but under NCOP v14 S11, it states:


"A motor vehicle under 4.5 tonnes GVM which is required to comply with ADR 24 may be equipped with tyres other than those listed on the tyre placard provided that:

the load rating of the tyres is not less than the lowest load rating listed on the tyre placard of the vehicle or equivalent variant of that model vehicle;

the speed rating of the tyres fitted to a passenger vehicle is at least 180 km/h (S) when the tyre placard requires a higher speed rating than S;

the speed rating of the tyres fitted to vehicles with special features for off-road use of at least 140 km/h N when the tyre placard requires a higher speed rating than N; "

Most states have committed to the NCOP regs, not all have yet ratified them, but should soon. The above obviously applies if you are fitting a tyre size NOT listed on the placard eg 265/60R18. It gets a little greyer if you're talking about a listed size. Show this to your tyre fitter.

Cheers,

Gordon

[MadJax]

I had a call from Cooper Tyres today. I asked about thier web site showing that the D3 & D4 can both fit the 265/60R18 110 tyres. He stated that you have to meet or exceed the minimum load rating or any rim size, which matches what gghagis said.

Now I need to track down a good price for a set of 4 (the spare can stay as it is)

[~Rich~]

I had a call from Cooper Tyres today. I asked about thier web site showing that the D3 & D4 can both fit the 265/60R18 110 tyres. He stated that you have to meet or exceed the minimum load rating or any rim size, which matches what gghagis said.

Now I need to track down a good price for a set of 4 (the spare can stay as it is)

Remember the spare must be the same overall size!
Damage may be done if this is not adhered to.

[MadJax]

Rich,

I had not thought of that. Still for now I am just going to replace the 4 worn ones. Not had to replace a tyre for 10 years.

Bugger I'm going to get one now!

[Dingmark Jim]

My D4's handbook has one page which looks to be out of the RRS handbook (ie, it talks about 255x50R19 tyres), so the placard should trump the book.

[dukemasterpro]

Had this happen to me when about to order at3 in 18 inch for a D4. The guy at bob jane said he could not officially recommend a tyre with a load rating of 110 when 112 was required. I can see that 109 is allowed with a 20" rim on the d4 - is the At3 going to be legal?? There does not seem to be any other at options in this side apart from the Pirelli atr ( which does not get a good rap and is more $$$)

[Tryanything]

Just got a set of Grabber ATs , 18" with 112 load rating and H speed rating. Happy with them so far. Got them from tyrepower camberwell in vic.

[rufusking]

Makes you wonder who comes up with all these figures. The standard D4 HSE rims are rated at 930kg so a 106 (950kg) load rating for the tyre would be above the rims capacity. The minimum load rating on the placard is 109 (1030kg), 100kg greater than the rims and the 112's nearly 200kg!

[Tryanything]

Tyre loads are quoted at the tyre rated speed. So if the rims have a higher speed rating it might be that they would have the equivalent of 110/112 load rating at lower speed?

Having said that I think the rear axle load rating is also about 1850kg or 925 per corner.

[gghaggis]

The tyre, as first point of contact and with more flexibility, will experience slightly higher load. Some of this is dissipated as heat, hence less is transmitted to the rim. Ergo the rim can be rated lower. One of the reasons that LR won't allow 22" rims and ultra-low profile tyres, is not enough is dissipated by the tyre and too much load is transmitted to the suspension components.

Cheers,

Gordon

[TerryO]

Had this happen to me when about to order at3 in 18 inch for a D4. The guy at bob jane said he could not officially recommend a tyre with a load rating of 110 when 112 was required. I can see that 109 is allowed with a 20" rim on the d4 - is the At3 going to be legal?? There does not seem to be any other at options in this side apart from the Pirelli atr ( which does not get a good rap and is more $$$)


I have had a set of AT3 265/60/18's on my D3 for about 25k now and they are excellent tyres, handle really well, little to no road noise, good in the wet and so far seem pretty good off road.

I bought mine not long after they came out for $300 a corner fitted.

cheers,
Terry

[bbyer]

It seems our LR3's here in North America require the XL, (Extra Load), Load Range rating as well as the Load Index, (such as 110), and Speed Rating, (such as H), minimums that are on the door plaque.

I note that the owners manual here seems silent on the XL requirement as does the door plaque, however the tyres that come standard on the LR3 and now LR4 are all marked XL , (Extra Load) or RF, (Reinforced).

Tire Tech Information - Load Range/Ply Rating Identification (http://www.tirerack.com/tires/tiretech/techpage.jsp'techid=55)

Tire Tech Information - How to Read Speed Rating, Load Index & Service Descriptions (http://www.tirerack.com/tires/tiretech/techpage.jsp'techid=35)

I just wondered if there was any formal side wall rigidity requirement in Australia?

Today, I removed my 18" winter tyres and installed my newly purchased summer tyres, Bridgestone Alenza H/L 255 55 R19 XL 111V M+S. The cost here was about $1,100 mounted and balanced from the local Firestone dealer.

The link below is to the tyres if anyone is interested in the specs.
Bridgestone*Dueler H/L Alenza (http://www.tirerack.com/tires/tires.jsp'tireMake=Bridgestone&tireModel=Dueler+H%2FL+Alenza&partnum=555VR9HLALNZXL&vehicleSearch=true&fromCompare1=yes&autoMake=Land) Rover&autoYear=2005&autoModel=LR3 HSE&autoModClar=

For winter, I have on order, the narrower Pirelli Scorpion Ice and Snow 235 65 R18 XL 110H M+S and Snowflake. These replace my Dunlop ST8000 M+S that are no longer made - was a pretty good tire to my mind as well.

Pirelli Scorpion Ice & Snow - Canadian Tire (http://tires.canadiantire.ca/view/product/TIRE/WINTER/0087982?add=0087982&htmlProductCode=0087970P)

[gghaggis]

It seems our LR3's here in North America require the XL, (Extra Load), Load Range rating as well as the Load Index, (such as 110), and Speed Rating, (such as H), minimums that are on the door plaque.

Just because it's fitted, doesn't mean it's legally required. I can't see how any statutory body could enforce a nebulous quantity such as "Extra Load" that has no quantitative definition? As long as you comply with the load and speed ratings, that should be sufficient. Let's not try to make it any more complicated than it is.

Cheers,

Gordon

[bbyer]

Trying to find a tyre in the stock sizes with an XL or RF rating can be a real complication.

Re my on order 235 65 R18 XL, the Pirelli Ice and Snow was about the only narrow winter tyre I could find here and it is a special order, (not regularly stocked), hence buy now, wait, and maybe we will have them for you in time for winter.

Talking to tyre shops guys, the apparent rational for the XL rating is that the 3 is short wheel base, (compared to conventional pickups here), heavy, (again compared to pickups that do not require the LT tyre), and SUV's like the 3 tend to get stuff piled on the roof rack and hence the centre of gravity starts to rise.

Some argue that the stiffer sidewall is a deemed solution for these realities if one considers them to be potential problems.

[gghaggis]

Some argue that the stiffer sidewall is a deemed solution for these realities if one considers them to be potential problems.
There _is_ no argument - if your tyre plaque doesn't specify "XL" (and it doesn't) you need only comply with the plaque and it's interpretation under the relevant statutes for your state. Anything else is tyre shops trying to squeeze a little more money off you.

Cheers,

Gordon

[bbyer]

Anything else is tyre shops trying to squeeze a little more money off you. Cheers, Gordon The tyre shops generally would have preferred I purchase non XL tyres as none had promotions on the XL variety, particularily in the OEM sizes. I do note however that when one calls up the 3 on say Tire Rack, the only tyres that display are XL rated. This also seems true of the computer data bases that the tyre dealer accesses.

It is I agree fortunate that the sticker is silent re the XL as that would suggest that the vehicle owner has a greater selection of tyres to choose from.

I just wonder why LR, at least here, ships the 3's and 4"s with the XL tyres? I am beginning to wonder if in the larger rim sizes with the reduced sidewall height, if the only tyres generally manufactured are XL or of Reinforced construction.

I am going to have to look at the door stickers on pickups around here. It seems that there are two sorts of tyres actually on the trucks, P-Metric SL, and LT or perhaps E rated. The LT tyres are seen most often on the 3/4 ton F250 type work truck and the P-Metric SL, on the half ton F150 truck that I regard as a Gentleman's pickup.

Tahoe and Escalade vehicles have SL tyres in the 18" rim but in the 20" and 22" rim size, the XL shows up. It just may be that in the larger rim sizes with reduced sidewall height tyres, the sidewalls tend to be stiffened, hence the XL or Reinforced rating shows up as a result of the realities of tyre construction.

This also seems true of the Lexus GX 460 range of SUV's that in Australia I gather have some Toyota designation. The 20" and 22" rims seem to have XL tyres called up but on the 18" rim, SL tyres are all that show up.

The designation may just be a natural result of how many wide low profile tyres on larger diameter rims are constructed.

[dukemasterpro]

Thanks for the feedback everyone! Very excited - taking the plunge on the at3's which being fitted right now. Will mean I have the spare Wrangler up for sale on Fleabay or via the forum if there's any interest.

[garethbrown2670@gmail.com]

I've destroyed 3 18in AT3s in the 110 load rating in the past 2 months, all doing Off Rod work at 20-25psi. All gone in the side wall. The Cooper dealer basically said that I should be using an LT construction, although a tyre isn't currently available in the right size. One's coming in 3-12 months' time.

[winaje]

I've destroyed 3 18in AT3s in the 110 load rating in the past 2 months, all doing Off Rod work at 20-25psi. All gone in the side wall. The Cooper dealer basically said that I should be using an LT construction, although a tyre isn't currently available in the right size. One's coming in 3-12 months' time.

Sounds typical of Cooper to make a comment like that. They should therefore state that the tyre you bought is unsuitable for offroad work when pressures are lowered. I'll bet they don't though.